Lightning-arrester.



I. F. MARTIN & H. N. MULLER.

LIGHTNING ARRESTER.

APPLICATION FILED AUG-I8, I915.

1 ,277,978. Patented Sept. 3, 1918.

2 SHEETSSH.EET 1.

WITNESSES I INVQENTOIIRS L F. MARTIN & H. N. MULLER.

LIGHTNING ARRESTER.

APPLICATION FILED AUG. I8. $91..

1 ,277,978. Patented Sept. 3,1918

2 3HEET$SHEET 2.

. Another defect in the construction of light- I UNITED STATES PATENT OFFICE.

JAMES FRANK MARTIN AND HENRY N. MfiLLER, 0F PITTSBURGH, PENNSYLVANIA; SAID MARTIN ASSIGNOR T0 SAID M'U'LLER;

LIGHTNING-ARRESTER.

Specification of Letters Patent.

Patented Sept. 3, 1918.

.To all whom it may concern:

Be it known that we, JAMES F. MARTIN, and HENRY N. MI'iLLER, citizens of the United States, both of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Lightning-Arresters, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a side elevation of one type of our arrester shown in position on the line.

Fig. 2 is an end elevation of the arrester on a larger scale.

Fig. 8 is a sectional view on the line III-III of Fig. 2.

' Fig. 4 is a cross sectional view on the line IVIV of Fig. 3, and

Fig. 5 is a sectional view on the line V-V of Fig. 3.

Heretofore different types of kinds of lightning arresters have been used for each difi'erent transmission line. There are several kinds and types for 500 volt, D. C. circuits such as are used in connection with railways, other types for 2200 volt, A. G. circuits, and'various complicated types for circuits of higher voltage. These arresters have all been constructed in accordance with the one elementary principle of providing a oint or points on the circuit which have a ower insulation value than other parts of the circuit, and when any excessive pressure passes over the line these points of lower 1nsulation value will break down and allow the current to pass.

In all of the arresters known to us the main principle of securin lightning protection has obscured such de ects as complexity, depreciationof arcin points, as well as construction which invo ves an inspection and manual operation at frequent intervals.

ning arres'ters arises from the proper mounting on the circuit relative to other apparatus on the circuit which endangers workmen, ease of inspection, danger from flashes and arcs which frequently set fire to and destroy adjacent inflammable supports of the circuit and other apparatus.

The object of our invention is to provide a lightning arrester of simple and inexpensive form which is adapted for a wide variety of uses, and with either alternating of repairing and maintenance will be low,

since the parts are of simple and durable character, inexpensive and easily replaced.

Another object of our invention is .to provlde an arrester which will take care of a predetermined portion of the line, so that all the arresters on the line, including those in the station, willnot be affected when the line receives a lightning charge, and thereby limits the area of stresses imposed by the stroke of lightning. Another object of our invention is to place the arrester in such a position that arcing caused by lightning will avoid all danger of setting the poles for supporting the line on fire, and at the same time prevents vibration due to wind and other stresses from displacing the adjustment of the arrester.

The precise nature of our invention will be best understood by reference to the accompanying drawings which will now be de scribed, it being premised, however, that various changes can be made in the details of construction and the general arrangement of the parts, without departing from the spirit and scope of our invention as defined in the appended claims.

Referring to the accompanying drawings, the reference character 2 designates the line to be protected, and which is supported on the usual insulator 3 connected to the cross arm 4: on the pole 5.

6 designates our improved lightning arrester in its entiret and which comprises a piece of iron pipe i, which we have shown surrounding the usual insulating material 8 0n the wire 2. Surrounding the pipe 7 which forms a choke core is a porcelain insulator 9,

and interposed between the insulator and the 1 pipe 7 is a layer of cushioning material 10. 11 is a nut for securing one end of the ipe 10 to the insulator, the other end thereo being secured by means of a cap 13, which engages a washer 14: interposed between the insulator 9 and the end of the cap. Both the cap 13 and the nut 11 engage screw threaded portions on the ends of the pipe 7. The opening through the cap 13 is somewhat larger than the thickest wire used for line purposes, so that the insulator is made of a standard form and ada ted to be used in connection with various ines. Surrounding the wire 2 and interposed between it and the wall of the cap 13, is a split bushing consisting oftwo members 15, and 1,5 are set screws for clamping the device in position on the line wire and making a good contact between the wire 2 and the cap 13. Secured in an orifice in the cap 13 by means of a screw 16 is an arcing horn 17, which is in electrical connection with the wire 2. Clamped about the insulator 9 is a split ring having members 18 and 19, which are secured in position by means of the screws 20. Adjustably connected to the member 19 by means of a set screw,2l is a second arcing horn 22, and 23 is a ground wire connected to the member 18 by means of a set screw 24. The arcing horn 22 is adapted to be adjusted longitudinally over the device with relation to the arcing horn 17 to space the two horns the proper distance from each other.

It will be readily seen that inasmuch as the iron pipe 7 has a relatively high inductance, in the event of lightning discharge or other abnormally high frequency current on the conductor 2, the impedance of such conductor will be enormously increased,

causing the foreign current to jump across the air gap between the arcing-horns and thus pass to ground.

The advantages of our invention result from the provision of a lightning arrester having a choke core and are horns, one of which is in direct electrical connection with the wire to be protected, while the other is adjustably mounted on the insulator. Another advantage results from the provision of means for directly'supporting the insulator on the wire to be protected and ata suiiicient distance from the wire supporting pole to prevent the pole from catching fire when the excessive current caused by lightning forms an arc across the gap between the horns.

Another advantage results from the provision of a device of this character which can readily be inspected from the ground, as all of the parts which are liable to be injured are in plain view.

A further advantage results from the combination of a choke core and horn gap in a simple form whereby the line can be sectionalized so that the effect of a lightning stroke is confined to a small portion of the line, and in which the choke core which is formed of a small piece of iron serves as a clamp for supporting the insulator.

We claim:

1. In a lightning arrester, the combination with a conductor to be protected, of an arcing-horn electrically connected to said condoctor, a. cooperating arcing-horn insulated from the conductor, and a piece of magnetic material in proximity to the conductor adj acent to the arcing-horns and offering sufficient impedance to the passage of a lightning discharge along the conductor to divert it from the conductor to the substantially as described.

2. In a lightning arrester, the combination with a conductor, of an arcing-horn electrically connected to the conductor, a coacting arcing-horn insulated from the conductor, and a choke core of magnetic material surrounding said conductor adjacent to the first named arcing-horn and oflering sufficient impedance to the passage of a lightning discharge along the conductor to divert it from the conductor to the arcing horns, substantially as described.

3. In a lightning arrester, the combination with a conductor, of an arcing-horn electrically connected to the conductor, a coacting arcing-horn insulated from the conductor, and a choke core in proximity to said conductor adjacent to the first named arcing-horn, said choke core comprising a tube of magnetic material surrounding said conductor and offering sufficient impedance to the passage of a lightning discharge along the conductor-to divert it from the conductor to the arcing horns, substantially as described.

4:. A lightning arrester, comprising an insulating body having an opening therein, a piece of magnetic material seated in said opening and having a passage therethrough for a conductor, an arcing-horn secured to the insulating body and having means for establishing a ground connection, and another arcing-horn having means for electrically connecting it to the conductor, substantially as described.

5. A lightning arrester, comprising an insulating body, a piece of pipe of magnetic material seated in said body, and having its opening arranged to form a passage for a conductor of smaller diameter than the pipe, an arcing-horn, means carried by said plpe whereby the arcing-horn may be electrically connected with said conductor, and a coact ing arcing-horn connected to the insulating body and having means for establishing a ground connection, substantially as described.

6. A lightning arrester, comprising an insulating body, a piece of pi e of magnetic material seated in said b0 y, and having its opening arranged to form a passage for a conductor of smaller diameter than the pipe, means for insulating the conductor from the pipe means for connecting an arcing-horn to the conductor, and'another arcing-horn carried by the insulating body, and having means whereby a ground connection may be established therefrom, substantially as described.

7. The combination with a line wire, of a tube of magnetic material supported by and surrounding the wire, an insulator supported by the tube, a grounded arcing horn mounted on the insulator and insulated arcing horns,

thereby from the wire, and a second arcing horn secured to the wire and mounted in proximity to the first horn.

8. The-combination with a line wire, of a plurality of lightning arresters distributed along the wire, each comprising a choke core of magnetic material surrounding the wire, and a gap for the lightning current to escape to ground, said choke core offering sufiicient impedance to the passage of a' lightning discharge along the line wire to divert it from the line wire to the gap, whereby the line is sectionalized and the effects of a lightning stroke confined to a section of a line.

9. The combination with a line wire, of a plurality of lightning arresters distributed along the wire, each comprising a choke core formed by a tube of magnetic material surrounding the line wire and offering sufficient impedance to the passage of a light ning discharge along the line wireto prevent the lightning from passing along the line wire past the lightning arrester, whereby the ,line is sectionalized and the eflects of a lightning stroke confined to a single section thereof.

10. The combination with a line wire, of a piece of magnetic material supported by and surrounding the wire, an insulator supported by the piece of magnetic material, and a gap comprising one member mounted on the insulator and insulated thereby from the Wire and connected to the ground, and

a second member secured tothe wire and mounted in proximity to the first member of the gap, substantially as described.

11. The combination with a line wire, of a lightning arrester comprising a tube of magnetic material supported by and surrounding the wire, an insulator supported by and surrounding the magnetic tube, a clamp surrounding the insulator, an arcing horn carried by said clamp and connected to ground, and a second arcing horn mounted on and supported by the wire in proximity to the first arcing horn.

In testimony whereof we have hereunto set our hands.

JAMES FRANK MARTIN. HENRY N. MULLER. Witnesses:

JESSE B. HELLER, H. M. CORWIN. 

